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Sub-problem 4b - Page 1 of 6

ID# C404B01

Sub-problem 4b: Off-Peak Operational Analysis of Alternate Route 7

Step 1. Set-up

We'll now use the information that we developed in sub-problem 4a as the basis for an operational analysis of the facility. This information provides the spatial basis for our analysis, the division of the facility into segments. We'll focus our discussion primarily on the eastbound portion of the facility but will review the results of the analysis for the westbound portion as well.

Let's consider what constitutes an operational analysis of a freeway facility. When we conduct an operational analysis, we are interested in the performance of the facility at a fairly detailed level, with enough information so that the analyst can assess how the facility will function, given both the demand and geometric inputs. The HCM analysis for a freeway facility produces several performance measures, including speed and density, as well as an estimate of the capacity of each of the segments of the facility, based on these inputs.

In order to conduct this operational analysis, we will need the following input data:

Exhibit 4-65. Alternate Route 7 Off-Peak Operational Analysis Input Data
Geometric data for each segment Traffic characteristics data Demand data
Segment length
Number of lanes on mainline and on-ramps
Average lane width on mainline
Terrain
Length of ramp acceleration and deceleration lanes
Free flow speed on mainline and ramps
Vehicle occupancy
Percent trucks and buses
Percent recreational vehicles
Driver population
 
Mainline entry demand for each time interval
Ramp demands for each time interval
Weaving demand on weaving segments

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